Simplify the expression. $ (3z^{5}+3z^{4}) - ( -3z^{7}+3z) $
Answer: Distribute any negative signs. $(3z^{5}+3z^{4}) + (3z^{7}-3z)$ Since we are adding polynomials, we can simply remove the parentheses. $3z^{5}+3z^{4} + 3z^{7}-3z$ Identify like terms. $ + \color{#DF0030}{3 z^5} + {3 z^4} + {3 z^7} - \color{#9D38BD}{3 z} $ Combine like terms. $ { 3 z^7} + \color{#DF0030}{ 3 z^5} + { 3 z^4} + \color{#9D38BD}{ -3 z} $ Add the coefficients. $3z^{7}+3z^{5}+3z^{4}-3z$